Merry Owen is desperate for her family to stay on their struggling farm in Wales, in the shadow of the Black Castle, owned by the de Courcys - enemies of Merry's family for generations. Skilled in the family tradition of archery, Merry is happiest out riding – but when she finds an overturned tree and a buried chest containing an ancient Welsh text, it leads her into a past filled with treasure, secrets and untold danger.